The IEEE interconnection standard recommends that the distributed resources (DRs) of a power distribution system be disconnected from the power distribution system when the voltage level falls below a recommended threshold to ensure that the distributed resources do not inject power onto the main power grid of the power distribution system. The IEEE interconnection standard is additionally based on the fact that as the voltage level of the distribution system drops, the distributed resource's voltage reference from the substation may no longer be available or may no longer be accurate.
Identifying the location of a fault in a traditional power system is a challenging task. Electric power only flows in one direction, i.e. from the substation to the various loads. Therefore, when a severe short circuit fault occurs in a distribution system, there is an associated current rise and accompanying voltage sag near the faulted node which extends to every node that is downstream of the faulted node. The fault protection system of a power distribution system currently known in the art responds to the short circuit fault by isolating the assumed faulted nodes and all the downstream nodes of the actual faulted node.
In a power distribution system containing distributed resources, most fault location technologies known in the art ignore the presence of the distributed resources by assuming either low distributed resource penetration or no power injection from the distributed resources during a fault situation. While there are additional fault location technologies known in the art that do consider the presence of distributed resources, these technologies do not consider a current limited system when a fault situation does occur.
Accordingly, what is needed in the art is a system and method for fault location identification in a power distribution system that addresses the presence of distributed resources and provides a current limited system when a fault occurs.